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Graphene has amazing applications for sensors due to its excellent performances like high strength and good conductivity, but the transfer issue is in the way of its application perspective. Direct growth of spherical graphene films (SGFs) on cemented carbide may offer a good avenue for various applications in sensor technology, especially for electrochemical sensors. Four common methods for graphene preparation are chemical stripping, chemical vapor deposition (CVD), metal catalysis, and laser fabrication; and subject to transfer issues during usage. In order to overcome this limitation, the fabrication of in-situ growth of SGFs on carbide is proposed as a solution for constructing sensor matrices. This review explores various in-situ SGFs and their potential applications in sensors. The findings presented here shed light on transfer-free graphene with controllable structures that can serve as excellent candidates for sensor matrices. [ABSTRACT FROM AUTHOR]

The corrosion behavior of WC-4.3 wt%MgO-2wt.%ZrO 2 composite in alkaline solution with 5 % oil-based cutting fluid as medium was studied by electrochemical and microstructure analysis methods. The results showed that WM2Z composite has better corrosion resistance than YG3 and YG6 in alkaline environment. A stable passivation film was formed inside the WC phase after dissolution on the surface, which was the key reason for its high corrosion resistance. However, large areas of WC phase fell off in cemented carbide. In the process of corrosion-friction coupling experiment, due to the more excellent corrosion resistance and mechanical properties of WM2Z composites, the corrosion resistance and friction properties of WM2Z composites are better than that of YG3 cemented carbide. The corrosion-friction coupling effect on WM2Z was low, and the degree of damage to the topography after the experiment was relatively light. [ABSTRACT FROM AUTHOR]

This interdisciplinary work concerns misorientations across various interfaces in spark plasma–sintered (SPSed) WC–Co cemented carbides, as well as how these misorientations affect the intergranular fracture. The whole boundaries in cemented carbides were divided according to the phases on the two sides of the boundary plane, and carbide/carbide grain boundaries were further divided according to the misorientation across the boundary plane. Stereological statistics and five‐parameter analysis were comprehensively performed on the concerned boundary types. For Σ2 carbide/carbide boundaries, multiple boundary structures are observed. How Σ2 twist inhibits intergranular fracture and how such boundary structure is formed are analyzed. For random carbide/carbide boundaries, the habit planes that they are terminated by are calibrated, and their responses to intergranular fracture are examined according to their energy anisotropy. For WC/α‐cobalt and WC/β‐cobalt phase boundaries, misorientations across these boundary planes and the corresponding crack propagation routines are illustrated. On these bases, approaches to improve the fracture strength of SPSed cemented carbides are suggested. [ABSTRACT FROM AUTHOR]

The deposition of diamond films on tungsten carbide-based tools can greatly improve the life and performance of cutting tools. However, the deposition of diamond coatings on cemented carbide (WC-Co) suffers from poor film-base bond strength. In this paper, diamond coatings were deposited of phytocrystalline metal micropowders (pure, Nb, Ti, Ta) pretreatment method and the properties of diamond films were analyzed by energy spectrometry (EDS), scanning electron microscopy (SEM), Raman spectroscopy and bonding strength test of diamond films. The results show that through the experiment of the pretreatment process of surface implanted crystal metal micropowder, the best implanted crystal metal micropowder was obtained, the surface quality of implanted crystal titanium (Ti) coating was improved, the diamond Raman peaks were sharp and the indentation cracks had a crack diameter of 389 μm, which is small and has the highest bond strength. The pretreatment process of phytocrystalline diamond micropowder can deposit high-performance diamond coatings and improve the bonding strength between the coating and the substrate film base. [ABSTRACT FROM AUTHOR]

Machining of metal matrix composites (MMC) is a challenging process as they are difficult to cut and cutting tools get worn out in a short time. In this paper, the performance of two industrial carbide grades and a cubic boron nitride (CBN) tool are assessed when machining of AZ91/SiC composites. Mg-based composites with different volume fractions and particle sizes are machined at various cutting conditions to evaluate the tools wear resistance and finished surface. The surface of the worn-out tools and machined samples are analyzed by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and roughness tester. Results revealed that the tool wear increased for composites reinforced by smaller particles regardless of the tool type. Additionally, tool grade TH1000 resulted in longer tool life when machining of Mg-based composites compared to the CP500 grade so that at a cutting speed of 70 m/min and feed rate of 0.1 mm/rev, tool life improved nearly 250%. CBN tools showed the best performance when machining of Mg-based composites as tools became worn out after 255 s which is considerable compared to carbide tools. Also, the finished surface caused by cemented carbide CP500 indicated the worst quality. [ABSTRACT FROM AUTHOR]

The aerospace industry has made extensive use of titanium alloy material due to its exceptional qualities, which include high strength, low weight, and resistance to corrosion. However, these qualities also pose challenges for the material's processing. This article examined the coated end mills for Ti6Al4V milling. First, an analysis was conducted on the solubility of Ti and Si elements. It was discovered that W and Co elements were far more soluble in Ti than Si and Zr elements, which could effectively stop element diffusion. Next, the base's composition was planned. It was discovered that when the amount of Al increased, the base's surface roughness increased, while its hardness and elastic modulus decreased. The binding force between the substrate and the base was greater at a 50:50 Ti:Al ratio. The H3/E2 was about 0.23 and the surface roughness was about 0.15 μm. TiSiN and TiSiN/ZrN functional layer properties were also examined. When Zr was added to TiSiN/ZrN coating, it improved the coating's hardness and elastic modulus, increased density, and decreased surface roughness and friction coefficient when compared to TiSiN coating. There was an increase in hardness by 8.09% and an increase in elastic modulus by 9.65%. The average coefficient of friction decreased from 0.315 to 0.299. Lastly, an analysis of the initial and intermediate tool wear was done using the Ti6Al4V milling experiment. It was discovered that adding Zr element could successfully extend the tool's cutting life by preventing adhesive wear. [ABSTRACT FROM AUTHOR]

The material for a cutting tool needs to be carefully selected to withstand high temperatures during cutting and have good wear performance. The use of cutting tools made from cemented carbide material was studied due to its potential in terms of mechanical properties that are ideal at high temperatures up to 1000 °C and being cheaper than other materials. This investigation of the dry wear of this cutting material focused on temperatures of 25 °C, 200 °C, and 300 °C, with loads of 50 N, 100 N, and 150 N. The weight loss, friction coefficient, and change of the pin microstructure were determined. It was found that the higher the temperature and load applied to the cemented carbide pin, the more the microstructure changed, and the percentage of weight loss increased up to 0.55%. The wear rate on the cemented carbide pins was higher when applied to a stainless steel disc compared to a mild steel disc. The simulation revealed that the von Mises stress on the stainless steel disc was 51.759 Pa, while that on the mild-steel disc was 60.379 Pa. This indicates that both materials did not fail because the von Mises stress was lower than the disc yield stress. [ABSTRACT FROM AUTHOR]

High-entropy alloys (HEA) as a kind of new binder for cemented carbide have garnered significant attention. In this work, WC/(17~25 wt.%)Al0.5CoCrFeNiTi0.5 cemented carbides were prepared by hot pressing sintering (HPS), and the reactions between WC powder and Al0.5CoCrFeNiTi0.5 powder during hot pressing sintering were elucidated. It found that different from traditional Co binder, the Al0.5CoCrFeNiTi0.5 binder effectively inhibited WC grain growth. During HPS, the decomposed W and C atoms from WC diffused into the Al0.5CoCrFeNiTi0.5 binder, reacted with the elements in the binder, and then formed the M(Co, Fe, Ni)3W3C phase. The back-diffusion of W and C atoms to WC grains was restricted by the Al0.5CoCrFeNiTi0.5 alloy and inhibited them from re-precipitating onto the large undissolved WC grains. As a result, the average size of WC grains in the cemented carbides was less than 200 nm. This work bright new insight into the grain refinement mechanisms of WC cemented carbide with HEA binder and provide a guidance for designing performance-stable WC/HEA cemented carbide and promoting their application. [ABSTRACT FROM AUTHOR]

WC-Co composites are widely used in cutting tools but are expensive and harmful due to Co in the composites. Alternatives, such as WC-Ni composites have inferior mechanical properties, as a result, WC-Co composites are used in most cutting tools. This study investigated whether adding yttrium oxide (Y2O3) to WC-Ni composites, fabricated from recycled tungsten carbide (WC) and Ni, improved their mechanical properties. Changes in the composites' microstructure and mechanical properties depended on the amount of Y2O3 added. Y2O3 reacted with WC during sintering, promoting the formation of W and reducing the proportion of C in the composite. The added Y2O3 accelerated the dissolution of W in the Ni matrix, and increased the fractions of the eta phase and solid solution phase. Ni is strengthened by the dissolution of W in Ni, thereby supplementing the low toughness of the eta phase and ultimately yielding WC – Ni with improved hardness and fracture toughness (HV: max. 15.4 GPa, KIC: max. 13.4 MPa∙m1/2) compared to WC – Ni without Y2O3 (HV: 13.5 GPa, KIC: 12.7 MPa∙m1/2). The method for improving the properties of WC – Ni composites by the addition of Y2O3 has a high possibility of commercialization because it does not necessitate process changes. [ABSTRACT FROM AUTHOR]

The effects of the addition of platinum group metals Ru, Rh and Ir on the microstructure and mechanical properties of cemented carbide at room and high temperatures were investigated. It was found that the increase in hardness by the addition of platinum group elements was due to the grain growth inhibition of WC and solid solution hardening of the binder phase. Furthermore, when creep deformation resistance was investigated as a mechanical property at high temperature, it was found that the strain rate of the WC-Co with Ru, Rh and Ir were lower than that of the WC-Co alloy. As a practical test, cutting test was conducted using martensitic stainless steel, which is used as a material for turbine blades. It was found that cemented carbides containing Ru had superior plastic deformation resistance compared to alloy without Ru. [ABSTRACT FROM AUTHOR]

This study was intended to investigate the mechanical property at high temperature and cutting performance of cemented carbide for machining of exotic materials, such as nickel alloys, cobalt alloys, and titanium alloys. Exotic materials are widely used for equipment and parts in the aerospace and automotive industries due to their superior heat and corrosion resistance. When machining exotic materials, its low thermal conductivity causes the cutting edge temperature to be higher than when cutting steel, and the hardness of the tool material decreases, resulting in extremely low tool life. However, because cemented carbide in particular contains metals in its composition, plastic deformation of the cemented carbide cannot be prevented even when the coating has sufficient heat resistance. The WC-Co-NiCr alloy, in which NiCr partially replaces Co as the binder phase of cemented carbide, has improved high-temperature properties while maintaining room temperature properties compared with conventional WC-Co alloys, and tool life has been improved in machining exotic alloys. [ABSTRACT FROM AUTHOR]

Ultrafine-grained binderless cemented carbides using 0.4 µm WC particles were prepared by adding Cr3C2, VC, TaC, βt and various sizes of Ti(C,N) particles. SEM observations of the polished and fractured surfaces revealed that the WC grains became finer after the addition of the carbides or carbonitrides. In the Ti(C,N)-added binderless cemented carbides, the WC grains became finer with decreasing Ti(C,N) particle size and increasing Ti(C,N) content. The grain size of WC in the binderless cemented carbide containing 0.1 μm Ti(C,N) was comparable to that of the Cr3C2-containing binderless cemented carbide, although not as fine as that of the VC-containing binderless cemented carbide. The binderless cemented carbides containing fine Ti(C,N) grains were harder and had higher strengths than the other carbides. The combined addition of fine Ti(C,N) and Cr3C2 resulted in more homogeneous WC grains. These results indicate that the grain growth inhibition of binderless cemented carbides varies depending on the type and grain size of the added carbonitrides. These findings will contribute to the future development of binderless cemented carbides. [ABSTRACT FROM AUTHOR]

Cemented carbide is a composite material of hard WC and soft Co, and has been widely used as a tool material because of its excellent balance of hardness and toughness. Among them, superfine cemented carbide with WC grain size of less than 1 μm is widely used as a base material for cutting tools and wear-resistant tools because it can achieve both high hardness and high strength. When using superfine cemented carbide as a cutting tool, it is essential to adopt the finer WC particles with higher Co dispersibility, in addition to the appropriate addition of grain growth inhibitors. If the WC particles can be finer, the hardness and transverse rupture strength of the alloy can be expected to improve. In addition, if Co particles, which are softer than WC particles, can be distributed more finely and homogeneously in the mixed powder, the mechanical properties of the alloy may be further improved. In this paper, we report on the improvement of Co dispersibility and the development of new ultra-fine WC, and introduce the cutting performance of the developed practical tools using above the WC powder. [ABSTRACT FROM AUTHOR]

Wear failure of oil drill bits leads to cost increase, and how to improve the abrasion resistance of cemented carbide (WC–Co) drill bits is an urgent problem, and deep cryogenic treatment (DCT) is a feasible method. The effect of DCT time (i.e., 0, 3, 6, 9, 12, 24, and 48 h) on the Vickers hardness, flexural strength, and wear rate of WC-Co with different Co contents (i.e., 5 wt%, 8 wt%, 10 wt%, and 12 wt%) was investigated. The results showed that the best DCT time for hardness, flexure strength, and abrasion resistance of WC-Co was 12 h. Compared with untreated (e.g., 0 h), the wear rates of WC-Co with different Co contents were reduced by 36%, 34%, 30%, and 19%, respectively at DCT-12. Compared with WC-12Co, the wear rate of WC-5Co with different DCT times was reduced by 75%, 77%, 78%, 78%, 80%, 79%, and 78%, respectively. The precipitation of η phase (Co6W6C), martensite phase transformation (α-Co to ε-Co), and the increase of residual compressive stress (RCS) of WC after DCT improved the hardness, flexural strength and reduced the wear rate of WC-Co. Based on the principle of frictional wear, a micro-cutting wear model considering Co content and DCT time is proposed, which can predict the evolution of the wear rate of WC-Co. The results of the study guide improving the wear resistance of drill materials.

WC-Co cemented carbide has applied in various fields due to its excellent properties. However， the defects of Co bonding phase in hard alloys， such as low hardness， low wear resistance， and poor high-temperature stability， limit their use. The research on Co phase strengthening has never been interrupted. Therefore， this paper aimed to integrate the various Co phase strengthening research efforts systematically and summarized the microstructural characteristics and mechanical properties of strengthening Co phase through traditional physical metallurgical strengthening （such as second phase strengthening， phase boundary strengthening， and solid solution strengthening） and particle strengthening. The hardness and toughness ranges of cemented carbide by different methods for Co phase were compared， the relationship of composition， microstructure， and property was established， and the advantages and disadvantages of various reinforcement methods were summed up. It provides a reference for the strengthened Co phase research and industrial production. According to the needs of working conditions， the performance indicators and service life of cemented carbide products are designed.

WC-Co composites are widely used in cutting tools but are expensive and harmful due to Co in the composites. Alternatives, such as WC-Ni composites have inferior mechanical properties, as a result, WC-Co composites are used in most cutting tools. This study investigated whether adding yttrium oxide (Y2O3) to WC-Ni composites, fabricated from recycled tungsten carbide (WC) and Ni, improved their mechanical properties. Changes in the composites’ microstructure and mechanical properties depended on the amount of Y2O3 added. Y2O3 reacted with WC during sintering, promoting the formation of W and reducing the proportion of C in the composite. The added Y2O3 accelerated the dissolution of W in the Ni matrix, and increased the fractions of the eta phase and solid solution phase. Ni is strengthened by the dissolution of W in Ni, thereby supplementing the low toughness of the eta phase and ultimately yielding WC – Ni with improved hardness and fracture toughness (HV: max. 15.4 GPa, KIC: max. 13.4 MPa∙m1/2) compared to WC – Ni without Y2O3 (HV: 13.5 GPa, KIC: 12.7 MPa∙m1/2). The method for improving the properties of WC – Ni composites by the addition of Y2O3 has a high possibility of commercialization because it does not necessitate process changes.

In modern industrial production, noise can reflect the cutting state of the workpiece and tool to a certain extent, and the noise collection method cannot interfere with the complex processing environment. To further improve the cutting performance of coated cemented carbide micro-textured tools, this paper builds a friction and wear test platform for micro-textured cemented carbide pins with AlSiTiN-AlCrN coating and titanium alloy discs. Based on the test noise signal, the relationship between friction and wear and the noise of the workpiece was studied by the Hilbert–Huang transform (HHT). Through the change of noise in different periods, the micro-texture and coating life of cemented carbide pin under other processing parameters were analyzed. Based on the influence of the interaction between processing parameters and micro-texture diameter on the test results, the test parameters were optimized. The results show that the change of noise signal during the test presents a "V" curve with the grinding process, which mainly affects the noise through the shift of pin-disc friction form and the anti-wear effect of micro-texture. The interaction mainly affects the test results by affecting the micro-texture diameter, laser energy concentration, and the roughness of the inner wall of the pit. The optimized micro-texture geometry and preparation parameters are as follows: scanning times is 8, micro-texture diameter is 50 μm, scanning speed is 1500 mm/s, micro-texture spacing is 170 μm, and laser power is 40 W. The research content of this paper provides a reference for improving the surface properties of cemented carbide. [ABSTRACT FROM AUTHOR]

In industrial practice, combining grain growth inhibitors (GGIs) with low carbon content effectively restrains WC grain growth in WC-Co cemented carbides. However, the intricate relationship between carbon content, WC grain microstructure, and GGI impact remains unresolved. This study investigates two WC-Co sample sets, maintaining constant VC inhibitor levels but varying carbon content near upper (HC) and lower (LC) limits. SEM analysis revealed distinct morphologies: HC displayed truncated prism shapes, exposing long basal and prismatic terraces, while LC exhibited a saw-tooth morphology with finer grains. EBSD stereology quantified anisotropic WC grain growth, revealing suppressed growth perpendicular to both basal (HC: 0.51 μm vs. LC: 0.38 μm) and prismatic planes (HC: 0.44 μm vs. LC: 0.37 μm) with decreased carbon content. Atomic-resolution EDS showed higher V solute excess in LC at WC(basal)-Co, WC(prismatic)-Co interfaces, and step corners (HC: 4.6, 0.9, and 4.4 atoms/nm2; LC: 5.5, 0.9, and 7.8 atoms/nm2). Our findings elucidate a clear physical understanding that a low carbon content enhances V atom solubility within liquid cobalt, increasing the thickness of complexions to quad-layer on WC (basal)-Co interfaces and forming V-rich nanoprecipitates at step corners. Those inhibitory effects further limited step flow, resulting in pronounced step bunching and a saw-tooth fine-grained morphology in LC sample. This study highlights that complexions housing more inhibitory solute elements exert a stronger drag effect on grain growth front migration. This approach has the potential for studying grain growth in anisotropic materials, highlighting the importance of constructing experimental complexion diagrams in engineering fine-structured ceramics and metals. [ABSTRACT FROM AUTHOR]

In bone-milling surgical procedures, the intense friction between the tool and bone material often results in high cutting temperatures, leading to the thermal necrosis of bone cells. This paper aims to investigate the effect of micro-texture on the tribological properties of YG8 cemented carbide in contact with bone. The main objective is to guide the design of tool surface microstructures to reduce frictional heat generation. To minimize experimental consumables and save time, numerical simulations are first conducted to determine the optimal machining depth for the texture. Subsequently, micro-textures with different shapes and pitches are prepared on the surface of YG8 cemented carbide. These textured samples are paired with bovine cortical bone pins featuring various bone unit arrangements, and friction and wear tests are conducted under physiological saline lubrication. The experimental results indicate that the appropriate shape and pitch of the micro-texture can minimize the coefficient of friction. The parallel arrangement of bone units exhibits a lower coefficient of friction compared to the vertical arrangement. This study holds significant implications for the design and fabrication of future micro-texture milling cutters. [ABSTRACT FROM AUTHOR]

In traditional cemented carbides, Co is mainly used as a binder. Recently, replacing Co with medium- to high-entropy alloys has shown significant improvements in hardness, fracture toughness, high-temperature oxidation resistance, and corrosion resistance, making it a research focus globally. Both the typical grain refiner Cr3C2 and medium- to high-entropy alloy binders affect the WC grain size in cemented carbides. This study investigates the synergistic grain refinement mechanism of Cr3C2 and medium- to high-entropy alloy binders on WC grains and their impact on the microstructure and mechanical properties of cemented carbides. The results show that increasing the Cr3C2 addition refined WC grains in the WC-CoNiFe alloy, increased coercivity, and enhanced hardness, with transverse rupture strength first increasing and then decreasing. The alloy achieved optimal performance at 0.6 wt.%Cr3C2, with a hardness of 91.25 HRA and transverse rupture strength of 3883.2 MPa. [ABSTRACT FROM AUTHOR]

Cemented carbide has been widely applied in the manufacturing industry due to the excellent wear resistance and corrosion resistance. As a typical difficult-to-machine material, it faces many challenges such as surface damage and tool wear in traditional machining. Therefore, many non-traditional machining methods based on energy fields have been gradually developed to machine cemented carbide and attract the increasing attentions. The purpose of this review is to offer the latest technological developments in various non-traditional machining processes and the hybrid machining methods of cemented carbide. According to the existing researches, the non-traditional machining methods based on thermal or chemical process exhibit some disadvantages in high efficient and precision machining of cemented carbide; the multi-energy field hybrid machining methods are developed to make up its disadvantages. However, in the multi-energy field hybrid machining, the coupling mechanisms of multiple energies and high-quality machining under multiple energy matching have not formed a unified and complete theoretical system. The development of these methods should be focused on interaction mechanism, energy transmission, and new machining tools. [ABSTRACT FROM AUTHOR]

Surface micro-texture has been shown to enhance wettability and reduce wear on cutting tools. However, there is limited research on how laser parameters impact the dimensional accuracy of surface texture and its wettability. This study focuses on producing arrayed groove textures on WC/Co cemented carbide surfaces using Nd: YAG laser, evaluating the effect of the laser parameters on surface topography and texture accuracy through microscopic observation and simulation. The results indicate that, with laser parameters such as a number of passes less than 5, approximately 16 W power, scanning speed of 100–150 mm/s, and pulse frequency of 30 kHz, the error between the groove width and laser spot diameter was 4.7%. Additionally, the study explores the impact of the groove texture on surface wettability using the solid droplet method and XPS analysis. Comparative experiments reveal that increased surface roughness enhanced oleophobicity, with surfaces exhibiting high texture accuracy and integrity showing improved oleophobic and spreading properties. Thus, the precise regulation of laser processes is crucial for maintaining surface texture integrity and enhancing surface wettability. [ABSTRACT FROM AUTHOR]

Diffusion welding of YG8 and 40Cr was carried out by spark plasma sintering. The influence of Ni interlayer with different thicknesses varying from 0 to 500 μm on the welding morphology and mechanical properties of joints was studied. The fracture position moved from the cemented carbide substrate toward the connection interface with the increase in the thickness of the Ni intermediate layer. The joint with nickel-free interlayer and 100-μm thick fractured during electrical discharge machining due to the large residual stress. The bending strength of the joints enhanced with the increase in the Ni intermediate layer from 200 to 300 μm, and a maximum flexural strength of 982 MPa was obtained with the thickness of the Ni intermediate layer to be 300 μm, which was up to 97% of the strength of the cemented carbide substrate. However, the further increase in Ni intermediate layer from 300 to 500 μm resulted in a decrease in the bending strength, which was due to the coupled effects of residual stress and interlayer plastic constraint. Besides, fracture cracks were also observed at the interface of Ni/40Cr with the thickness of Ni intermediate layer to be 400 and 500 μm. The formation of Kirkendall pores in the interface of Ni/40Cr due to different diffusion coefficients of Fe (1.468 × 10−14 m2/s) and Ni (2.15 × 10−14 m2/s) was responsible for the crack initiation and propagation in the Ni/40Cr interface. [ABSTRACT FROM AUTHOR]

Direct ink writing of 3D WC-Co with conformable green bodies was achieved benefiting from the highly flexible WC-Co paste with high solid loading. Rheology properties of the paste, microstructure of the 3D structure was investigated. Organic-based paste of WC-8Co with a high solid content of 91 wt% were prepared, which exhibited shear thinning behavior and had a high storage modulus, two key parameters for ensuring the smooth printing. After secondary molding, 3D WC-Co green bodies with overhanging structure and no cracks were confirmed through secondary treatment of twisting or bending. Sound 3D structures with uniform and dense microstructure were obtained after debinding and sintering in vacuum. This work showed a facile route for the fabrication of 3D bone cemented carbides by direct ink writing with flexible green bodies. [ABSTRACT FROM AUTHOR]

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In order to explore the influence of high-order micro-texture parameters on the friction, wear, and vibration characteristics of coated cemented carbide pin surfaces, expand the research field of textured coating modification processes. Firstly, a laser was used to prepare micro-texture on the surface of the cemented carbide pin, and AlCrN coating was carried out. The friction and wear test platform of the micro-textured physical vapor deposition (PVD)-coated cemented carbide and titanium alloy substrate was built, and the friction vibration and acoustic vibration signals were obtained as the main analysis media. Secondly, according to the characteristics of the test signal, three time-frequency images are analyzed and compared. The continuous wavelet transform (CWT) method with a better time-frequency analysis effect is selected. Finally, the characteristics and regularity of friction vibration and acoustic vibration are analyzed by using the gray mean of the CWT time-frequency image. The influence mechanism of high-order micro-texture parameters on the surface characteristics of coated cemented carbide pins was obtained. It is concluded that the high-order micro-texture is 1.58% higher than the traditional scale in the stability of friction vibration, 4.47% higher in the stability of acoustic vibration, and 13.16% lower in the friction force, which proves the progress of the size improvement. It provides a practical basis for the extension research of cemented carbide surface modification. [ABSTRACT FROM AUTHOR]

Ball milling is a key processing step in the manufacture of cemented carbide. That process is widely used at different scales: both industrial applications and laboratory experimentations. A bowl from the milling machine has however exploded during its use, leading to the destruction of the milling machine lid, the scattering of the powder that was milled, and a delay in the further experiments of the lab. The material to be milled was a mixture of high-entropy alloy aimed for use as a binder in tungsten carbide composite materials. The failure analysis study has been achieved with conventional methods such as x-ray diffraction, x-ray fluorescence, microstructures (by optical and scanning electron microscopies), and hardness testing. [ABSTRACT FROM AUTHOR]

In this study, WC-12Co cemented carbides were prepared by laser powder bed fusion (LPBF) on a WC-20Co substrate. The effects of the scanning speed and the substrate on the microstructure, mechanical properties and wear characteristics of the WC-12Co cemented carbide were investigated. The results showed that an alternating distribution of coarse and fine WC grains is observed in the LPBF-prepared WC-12Co cemented carbides. As the laser scanning speed decreases or the laser energy density increases, the WC phase gradually decomposes, accompanied by the loss of C and the formation of ƞ phases. WC-12Co cemented carbides produced at a lower scanning speed exhibit a higher density of thermal cracks, while those produced at a higher scanning speed have a larger number of pores. As the laser scanning speed increases, the transverse rupture strength (TRS) first increases to a maximum value of 823.13 MPa and then decreases. The variation of TRS is mainly attributed to the evolution of the brittle ƞ-phase and metallurgical defects. For WC-12Co cemented carbides formed at low scanning speeds, the brittle η-phase may fracture and cut through the matrix during the friction process, leading to an increase in coefficient of friction (COF) and wear mass loss. For samples formed at high scanning speeds, the formation and detachment of the shear layer could accelerate the friction process and undermine the wear resistance of the WC-12Co cemented carbide. Therefore, the sample prepared at the scanning speed of 400 mm/s shows the best wear performance.

To investigate the temperature characteristics of Laser-Assisted Cutting (LAC) in relation to cemented carbide, a theoretical model for LAC temperature was established based on heat conduction theory. Finite element simulations were conducted to analyze the surface temperature distribution and internal temperature distribution of cemented carbide during the LAC process. And an empirical formula for the LAC temperature of cemented carbide was obtained through temperature testing, and the model was experimentally validated. In addition the influences of the cutting temperature on the material machinability were experimentally studied. The results showed that the factors affecting cutting temperature ranked in order of importance are laser power, laser traversal speed, laser spot diameter, distance between cutting edge and spot center, cutting depth, and cutting speed. The cutting temperature trends were consistent under different processing parameters. In comparison with traditional cutting, the LAC method reduced the radial thrust force (Fx), tangential force (Fy), and axial thrust force (Fz) by 20.00, 27.14, and 53.19% respectively. The surface roughness of the workpiece was reduced by 50%, resulting in a flat and smooth surface with improved machinability. [ABSTRACT FROM AUTHOR]

To satisfy the needs of precision machining, ultrafine tungsten carbide (WC)-based cemented carbide with fine grain size and excellent mechanical properties was prepared. Ultrafine cemented carbide was prepared by spark plasma sintering (SPS) using WC, Co as raw materials and metal elements V, and Cr as additives, and the effects of metal elements on the microstructure and mechanical properties of cemented carbide were investigated. The results show that the specimen (91.6WC-1.2V-1.2Cr-6Co) prepared at 1350 °C, 6 min, 25 MPa has the best mechanical properties (HV 2322.9, KIC 8.7 MPa·m1/2) and homogeneous microstructure. The metal elements could react with WC to form a (W, V, Cr) Cx segregation layer, which effectively inhibits the growth of WC grains (300 nm). The combination of SPS and metal element additives provides a new approach for the preparation of ultrafine cemented carbides with excellent properties. [ABSTRACT FROM AUTHOR]

The laser ultrasonic composite cutting (LUCC) process was proposed by combining laser heating-assisted cutting (LHAC) and elliptical ultrasonic vibration cutting (UVC). In the process of cutting experiment, cubic boron nitride (CBN) is selected as the tool's material. The wear morphology and wear appearance of the tools were observed by super depth-of-field microscopy and scanning electron microscopy (SEM) to research the wear characteristics and wear mechanism of CBN tools during LUCC of cemented carbide. Compared with conventional cutting (CC), UVC and LHAC, during LUCC of cemented carbide with CBN tools the tool wear are significantly reduced by 45.11%, 28.92%, and 17.39% respectively, the cutting force are decreased by 61%, 44%, and 46% respectively, and the surface roughness are lowered by 77%, 55%, and 62% respectively, therefore the tool life is obviously lengthened. Moreover, the tool flank wears model of during LUCC of cemented carbide was established and verified by the tool flank face wear test. The results show that when the CBN tool is used for LUCC of cemented carbide, the wear band on the tool's rake face is basically parallel to the cutting edge and is in the shape of a long strip, and the wear band on the tool's flank face shows a triangular-shaped wear band accompanied by shallow pits and grooves; In the process of the LUCC of cemented carbide, the main causes of CBN tool wear include adhesive wear, oxidation wear and abrasive wear are the main causes of CBN tool wear during LUCC of cemented carbide; The faster the cutting speed, the bigger the error among the experimental value with the calculated value, and the wear of tool's flank face during LUCC of cemented carbide gradually increased. [ABSTRACT FROM AUTHOR]

Doping rare earth elements in WC-Co cemented carbide can make the additives and the original elements form a complex structure, thus further strengthening the overall structure and improving the comprehensive properties of cemented carbide. In this paper, the rare earth element La is added to the cemented carbide WC-Co. Through the construction of atomic cell and interface, the influence of La element on WC-Co cemented carbides is analyzed. The influence law of La atom on other atoms is explained according to analyze the adhesion work, reaction enthalpy, electronic state density and charge density. The results show that more covalent bonds are generated near lanthanum atoms at the interface junction, which enhances the interface bonding strength, makes the whole structure more stable, and the unit cell doped with La element has better stability and improves the overall toughness. The calculation results can provide data for enhancing the performance of cemented carbides and provide a theoretical basis for doping rare earth lanthanum in WC-Co cemented carbides in the future. [ABSTRACT FROM AUTHOR]

The special mechanical properties of cemented carbide with many excellent properties such as high modulus of elasticity, hardness, and strength will cause complex stress distribution due to excessive force and heat in the process of precision manufacturing, which will affect precision retention and endurance limit. Given excessive force and heat distribution and the conflict between brittleness and strength, ultrasonic elliptical vibration turning (UEVT) technique has become an irreplaceable method to machining cemented carbide. However, the addition of elliptical vibration changes the force and heat during cutting, which makes the influence on the residual stress of cemented carbide complicated. Therefore, based on the kinematic characteristics of turning carbide endface, an equivalent three-dimensional simulation model of thermo-mechanical coupling is established. It is found that the simulation models can predict residual stress with high accuracy. Ultrasonic-assisted vibration machining can effectively improve surface residual stresses, thus improving the quality of the machined surface. With the increase of cutting velocity, the duty ratio of cutting increases, and the surface residual stress has a decreasing trend; with the increase of ultrasonic amplitude, the duty ratio of cutting decreases, and the residual stress on the surface tends to increase. [ABSTRACT FROM AUTHOR]

Micro-milling of cemented carbides is a challenging task due to their high hardness, low toughness and high wear resistance. Ensuring good surface quality and dimensional accuracy is crucial for extending parts service life, which in turn enhances economical and environmental sustainability. This paper is mainly focused on evaluating surface formation mechanisms, scale effects, fracture behaviour and chip formation using distinct cemented carbide micro-milling tools with multi-layer diamond HF-CVD. In order to achieve higher precision and more efficient micro-milling operations on WC-15Co and WC-10Co, a systematic experimental approach has been carried out. The influence of cutting parameters, achievable surface quality and defects occurrence were thoroughly examined. Experimental results evidence the influence of operational conditions on the chip formation of cemented carbides as well as an important impact of the utilized cutting tool. Micro-pits, cracks, thin ploughing layer and fractured workpiece edges are amongst the observed surface damage mechanisms. A ductile cutting regime of the high-hardness composite material is confirmed, exhibited by the plastic deformation even when small depths of cut are considered. [ABSTRACT FROM AUTHOR]

The change in the structure and physicomechanical properties of sintered binding WC–6Co, and WC–15Co cemented carbides because of the action of high pressure (8 GPa) and high temperature (HPHT) in the Toroid installation is investigated. It is established that as a result of HPHT treatment at temperatures above the melting point of the metal binding phase, there is a decrease in the coercive force of the experimental alloys due to the growth of the carbide grain of the alloy. In alloys with a higher content of the binding phase, Co3W, Co6W6C intermetallic phases, and oxide of the Co2O3 type are formed. The hardness of the HPHT treated WC–6Co alloy samples decreases due to the growth of the alloy carbide grain, and the hardness of the treated WC–15Co samples increases due to the formation of intermetallic phases. [ABSTRACT FROM AUTHOR]

Cemented carbide used in the rotor of a mud pulser is subjected to the scouring action of solid particles and corrosive mud media for a long time, which causes abrasive wear and electrochemical corrosion. To improve the wear and corrosive resistance of cemented carbide, samples with different cobalt content (WC-5Co, WC-8Co, and WC-10Co) receive deep cryogenic treatment (DCT) at −196 °C for 2.5 h. An optical metalloscope (OM) and X-ray diffractometer (XRD) are used to observe the phase changes of cemented carbides, and the XRD is also used to observe the change in residual stress on the cemented carbide's surface. A scanning electron microscope (SEM) is used to characterize the wear and electrochemical corrosion surface microstructure of cemented carbides (untreated and DCT). The results show that the DCT promotes the precipitation of the η phase, and the diffraction peak of ε -Co tends to intensify. Compared with the untreated, the wear rates of WC-5Co, WC-8Co, and WC-10Co can be reduced by 14.71%, 37.25%, and 41.01% by DCT, respectively. The wear form of the cemented carbides is mainly the extrusion deformation of Co and WC shedding. The precipitation of the η phase and the increase in WC residual compressive stress by DCT are the main reasons for the improvement of wear resistance. The electrochemical corrosion characteristic is the dissolution of the Co phase. DCT causes the corrosion potential of cemented carbide to shift forward and the corrosion current density to decrease. The enhancement of the corrosion resistance of cemented carbide caused by DCT is due to the Co phase transition, η phase precipitation, and the increase in the compressive stress of cemented carbide. [ABSTRACT FROM AUTHOR]

In this study, cemented carbide was machined to a high quality using polycrystalline diamond (PCD) ball end mills characterized by various surface textures. The effect of the surface texture of the tools on the machining characteristics was studied using two types of PCD tools featuring abrasive diamond grains at various protrusion heights. In addition, a single crystal diamond tool with the same shape as that of the PCD tool was fabricated, and the experiment was repeated to study the differences in machining characteristics. The polished PCD tool yielded a high-quality machined surface with an average surface roughness of 1 nm. The polished PCD tool yielded superior sample surface roughness compared to the PCD tool for feed rates of 10–500 mm/min. The use of a polished PCD tool enables the efficient elimination of material through plastic flow, leading to the attainment of a high-quality machined surface while preventing the adhesion of materials on the tool surface. A single crystal diamond tool can also be used for machining cemented carbide within a feed rate range of 10–200 mm/min; however, its performance is inferior to that of a polished PCD tool. Experiments confirmed that the polished PCD tool was the most effective among the tested tools for the precision machining of cemented carbide. [ABSTRACT FROM AUTHOR]

Determining toughness properties is crucial for the development of components made of brittle materials, especially at the microscale. Numerous methods rely on establishing a limit load that triggers the propagation of a pre-cracked specimen. The primary challenge lies in accurately and repeatably determining this limit load value. In this study, we introduce a coupled numerical-experimental approach to determine the stress intensity factor at the microscale using a micro-bending test on pre-notched cemented carbide micro-cantilevers. Specimens are fabricated through micro-electrical-discharge milling, and the initial crack is generated using a focused ion beam process to ensure a repeatable crack shape. Geometries are defined to validate beam theories.Cycling bending tests, employing nanoindentation with three types of loading (fatigue-like, progressive repeated, and ramping sinusoidal loadings), are utilized to ascertain fracture toughness properties of tungsten carbide material at the microscale. Micro-indentation is also conducted conventionally to compare hardness at meso and micro-scales. Analytical methods and finite element analysis are employed to extract the critical stress intensity factor. The cyclic bending test with the proposed ramping sinusoidal loading demonstrates a time shift between the applied force and the displacement, enabling accurate and repeatable detection of the initiation of crack propagation. The primary contributions are associated with the development of a micro-bending test on precracked microcantilevers with ramping sinusoidal loading applied by a nanoindentor device. The miniaturization of specimens and tests, for an equivalent grain size, does not result in a scale effect on toughness properties.

WC-8Co cemented carbide was prepared by a high-temperature liquid phase sintering in argon at 5-200 Pa. Three microtextured grooves with a spacing of 500, 750, and 1000 μm were prepared on the surface of WC-8Co cemented carbide. TiAlCrSiN multi-element hard coating was deposited on the WC-8Co cemented carbide microtextured surface with multi-arc ion plating technology. The Vickers hardness and fracture toughness of coated and uncoated WC-8Co cemented carbide with or without a microtextured surface were investigated. The effect of different microtextured spacing on the interface bonding strength of the TiAlCrSiN coating was analyzed. The results show that with the reduction of the microtextured spacing, the Vickers hardness of the cemented carbide slightly decreases, and the fracture toughness slightly increases. The microtextured surface can improve the interface bonding strength between the coating and the substrate. The smaller the microtextured spacing, the larger the specific surface area and the higher the surface energy, so the interface bonding strength between the coating and the substrate increases.

In order to solve the problem that it is difficult to grow diamond films with high binding force on the surface of high cobalt cemented carbide, the Cr/CrSiN film was used as the transition layer, and the nanocrystalline diamond films (NCD), the submicrocrystalline diamond films (SMCD) and the microcrystalline diamond films (MCD) were deposited on the cemented carbide by hot filament chemical vapor deposition method, and their binding forces were studied. The results show that the Cr/CrSiN transition layer can be used to deposit diamond films with excellent bonding strength on the surface of high cobalt cemented carbide. NCD has the best binding force, followed by SMCD, and MCD has the worst binding force. When the grain size of the diamond film increases, the bonding forces of the diamond film weaken due to the poor toughness of the diamond films and severe carbonization of the transition layer. When the crystal size of the diamond film increases, the binding force of the diamond film becomes weak due to the poor toughness of the diamond film and serious carbonization of the transition layer.

Cemented carbide is a kind of hard to process material with high hardness, strength, wear resistance and corrosion resistance. In order to achieve efficient and precise cutting of hard alloy materials, this paper takes polycrystalline diamond (PCD) tool milling of WC-15Co hard alloy as the research object. Based on the Bifano cutting thickness model, the critical cutting thickness of WC-15Co is calculated, and then compared with the maximum cutting thickness corresponding to the cutting parameters. The range of cross-domain milling parameters for the coexistence of brittle-domain cutting and ductile-domain cutting of the processed material is preliminarily determined. On this basis, through high-speed milling experiments, the effects of cutting parameters such as feed rate per tooth, radial cutting depth, and cutting speed on the machined surface quality and cutting force of the specimen are analyzed, and the mechanisms are explored. The results show that under the cross-domain milling parameters, that is, when the cutting speed is 300 m/ min, the cutting rate per tooth is controlled within 11 μm/z and the radial cutting depth is less than 1 mm. The cutting surface in the ductile-domain can be obtained, the surface roughness is less than 0.2 μm, and there is no obvious brittle damage defect on the surface. The highest material removal rate can reach 157 mm³ / min, significantly higher than that of the 43 mm³ /min during the pure ductile-domain cutting. [ABSTRACT FROM AUTHOR]

Precision edge preparation techniques for cemented carbides enable optimization of the geometry of tools' cutting edges. These techniques are frequently used in high-stress environments, resulting in substantial improvements in tools' cutting performance. This investigation examined the impact and evolution of cutting edge parameters and resulting surface finishes as a function of dry-electropolishing time on an end-mill. Findings demonstrate enlargement of the cutting edge radius, a decrease in surface roughness, and the mitigation of defects induced during previous manufacturing stages (i.e., smashed ceramic particles, burrs, chipping, etc.). Additionally, a direct correlation between dry-electropolishing time and primary cutting edges' micro-geometry parameters has been established. [ABSTRACT FROM AUTHOR]

Emerging laser precision machining, particularly using pulsed lasers, enlightens the innovation and functionalization of cemented carbides. These backbone materials of the tooling industry are usually considered difficult to machine or shape using conventional mechanical approaches. The coating of cemented carbide tools, deemed to improve their mechanical and thermal properties, is a common supplementary surface treatment prior to their application. This work aims to study the synergic effects of nanosecond laser ablation and coating deposition on the surface, as well as the mechanical integrity of cemented carbides. In this regard, two plain WC–Co grades with different metallic binder content (10%wtCo and 15%wtCo) were first processed by a short-pulsed nanosecond laser. Subsequently, an AlTiN film was physically vapor-deposited on the laser-processed surfaces. The resulting surface integrity was assessed in terms of topographical, morphological, and microstructural changes. Mechanical integrity was evaluated in terms of indentation and sliding contact responses using Vickers hardness and scratch tests, respectively, the latter including frictional, penetrating, and sliding performances under selected surface processing conditions. In general, the nanosecond laser ablation proved to be beneficial for the mechanical integrity of coated cemented carbides in most studied cases, as it increased surface hardness, reduced penetration depth, and hindered damage during sliding. This was the case despite a slight increase in surface roughness, as well as minor morphological and microstructural changes at the coating–substrate interface, discerned. [ABSTRACT FROM AUTHOR]

Cracks usually generate during the formation of beads composed of a WC-12mass%Co cemented carbide by the laser metal deposition (LMD). Measuring temperatures of the formed bead and substrate during the LMD process is important for realizing crack-free beads. In this study, temperatures of the substrate around the formed bead during the LMD process were measured using a thermoviewer. Temperatures of the formed beads during the LMD process were predicted by simulation based on the thermal conduction analysis using the experimentally measured temperatures of the substrate. The experimental results obtained during forming the WC-12mass%Co cemented carbide beads on JIS SKH51 (ISO HS-6-5-2) substrates showed that the maximal temperatures of the substrates at 0.2 mm away from the center of the formed beads ranged from 229 °C to 341 °C at laser powers ranging from 80 W to 160 W. The predicted maximal temperatures of the formed beads were in the range of 2433 °C to 4491 °C in the simulation using a laser absorption coefficient of 0.35 for the substrate. Validity of these simulation results was discussed based on the melting point of the substrate and microstructures of the formed WC-12mass%Co cemented carbide beads. [ABSTRACT FROM AUTHOR]

Abstract Cemented carbide 91 wt% WC–3 wt% TiC–6 wt% Co was sintered by spark plasma sintering at different temperatures of 1200 °C, 1300 °C, and 1400 °C and the effect of sintering temperature on the microstructure and properties of this type of composites, such as total density, apparent density, hardness, and fracture surface were measured and observed using Field Emission-Scanning Electron Microscopy, Optical Microscopy, X-ray diffractometry and mechanical test instruments. The results showed that the apparent density of the samples increased with increasing sintering temperature from 1200 to 1300 °C from 13.98 to 14.23 g/cm3, respectively. But in the sample sintered at 1400 °C, the density was reduced to 14.20 g/cm3. An increase in the fluidity of the cobalt phase and capillary pressure is the cause of the increase in density at higher temperatures, the cobalt phase has evaporated and the density has decreased slightly. Also, Vickers micro-hardness results showed that the hardness of sintered samples increased with the increase of sintering temperature. For the sample sintered at 1200 °C the hardness value of 1746.41 kgf/mm2 was obtained which increased with increasing sintering temperature from 1300 to 1400 °C from 2094.33 to 2280.97 kgf/mm2, respectively. The amount of core–shell structure [including TiC-core and (W, Ti)C-shell] increased with increasing the sintering temperature process. As a result, the hardness also increased. At the optimum sintering temperature, it was found that TiC inhibited the grain growth of tungsten carbide. In addition, as expected, the grain growth of tungsten carbide increased with increasing sintering temperatures. Examination of the fracture surface of sintered samples at different temperatures also showed that brittle fracture involves fracture.

High-entropy alloys (HEA) as a kind of new binder for cemented carbide have garnered significant attention. In this work, WC/(17~25 wt.%)Al0.5CoCrFeNiTi0.5 cemented carbides were prepared by hot pressing sintering (HPS), and the reactions between WC powder and Al0.5CoCrFeNiTi0.5 powder during hot pressing sintering were elucidated. It found that different from traditional Co binder, the Al0.5CoCrFeNiTi0.5 binder effectively inhibited WC grain growth. During HPS, the decomposed W and C atoms from WC diffused into the Al0.5CoCrFeNiTi0.5 binder, reacted with the elements in the binder, and then formed the M(Co, Fe, Ni)3W3C phase. The back-diffusion of W and C atoms to WC grains was restricted by the Al0.5CoCrFeNiTi0.5 alloy and inhibited them from re-precipitating onto the large undissolved WC grains. As a result, the average size of WC grains in the cemented carbides was less than 200 nm. This work bright new insight into the grain refinement mechanisms of WC cemented carbide with HEA binder and provide a guidance for designing performance-stable WC/HEA cemented carbide and promoting their application.

In traditional cemented carbides, Co is mainly used as a binder. Recently, replacing Co with medium- to high-entropy alloys has shown significant improvements in hardness, fracture toughness, high-temperature oxidation resistance, and corrosion resistance, making it a research focus globally. Both the typical grain refiner Cr3C2 and medium- to high-entropy alloy binders affect the WC grain size in cemented carbides. This study investigates the synergistic grain refinement mechanism of Cr3C2 and medium- to high-entropy alloy binders on WC grains and their impact on the microstructure and mechanical properties of cemented carbides. The results show that increasing the Cr3C2 addition refined WC grains in the WC-CoNiFe alloy, increased coercivity, and enhanced hardness, with transverse rupture strength first increasing and then decreasing. The alloy achieved optimal performance at 0.6 wt.%Cr3C2, with a hardness of 91.25 HRA and transverse rupture strength of 3883.2 MPa.

In bone-milling surgical procedures, the intense friction between the tool and bone material often results in high cutting temperatures, leading to the thermal necrosis of bone cells. This paper aims to investigate the effect of micro-texture on the tribological properties of YG8 cemented carbide in contact with bone. The main objective is to guide the design of tool surface microstructures to reduce frictional heat generation. To minimize experimental consumables and save time, numerical simulations are first conducted to determine the optimal machining depth for the texture. Subsequently, micro-textures with different shapes and pitches are prepared on the surface of YG8 cemented carbide. These textured samples are paired with bovine cortical bone pins featuring various bone unit arrangements, and friction and wear tests are conducted under physiological saline lubrication. The experimental results indicate that the appropriate shape and pitch of the micro-texture can minimize the coefficient of friction. The parallel arrangement of bone units exhibits a lower coefficient of friction compared to the vertical arrangement. This study holds significant implications for the design and fabrication of future micro-texture milling cutters.